Codex 0.153.4

Released: 2026-09-04

Release notes

BUGFIX

Astra now visible in the bundled model picker, becomes default when unconfigured

When you open Codex to start coding, if no specific model is explicitly configured, Astra now serves directly as the bundled default model. Previously, Astra could fail to appear properly in the bundled model picker (a menu for switching between different AI versions); this update fixes the visibility issue, so it now shows up clearly in the selection list for you to pick; as long as you haven't specified another model, it automatically takes over your development work.

This lets everyday operations without a configured preferred model use Astra directly, and it can also be found quickly in the list when switching.

FEATURE

Astra's async-question guidance updated to ask only when the session provides the tool

When you hand Astra a complex task, its behavior of asking background confirmation questions is now more precise. This update adjusts Astra's built-in guidance, explicitly restricting it to initiate asynchronous questions to you (a mechanism that waits for a reply in the background without blocking your current work) only when the tool for questions is actually available in the current session. Previously, if the environment didn't provide the corresponding tool, the model could still attempt to send background questions; now with this condition in place, the questioning action only triggers in a supported environment.

As a result, the session can keep running stably even when the questioning module is unavailable, without being interrupted by an ill-timed question.

Original changelog

Original changelogAstra now visible in the bundled model picker, becomes default when unconfigured
Fixed Astra’s visibility in the bundled model picker and made it the bundled default when no model is explicitly configured. (#42874)
Original changelogAstra's async-question guidance updated to ask only when the session provides the tool
Updated Astra’s guidance to use asynchronous questions only when the tool is available in the session. (#42878)